From f4c1dbb0dfee79ecb4443777780470f6698044e9 Mon Sep 17 00:00:00 2001 From: Hiroshi DOYU Date: Wed, 16 Nov 2011 17:36:37 +0200 Subject: [PATCH 1/2] ARM: IOMMU: Tegra20: Add iommu_ops for GART driver Tegra 20 IOMMU H/W, GART (Graphics Address Relocation Table). This patch implements struct iommu_ops for GART for the upper IOMMU API. This H/W module supports only single virtual address space(domain), and manages a single level 1-to-1 mapping H/W translation page table. Signed-off-by: Hiroshi DOYU --- drivers/iommu/Kconfig | 11 + drivers/iommu/Makefile | 1 + drivers/iommu/tegra-gart.c | 451 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 463 insertions(+), 0 deletions(-) create mode 100644 drivers/iommu/tegra-gart.c diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 6bea696..4562698 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -142,4 +142,15 @@ config OMAP_IOMMU_DEBUG Say N unless you know you need this. +config TEGRA_IOMMU_GART + bool "Tegra GART IOMMU Support" + depends on ARCH_TEGRA_2x_SOC + default y + select IOMMU_API + help + Enables support for remapping discontiguous physical memory + shared with the operating system into contiguous I/O virtual + space through the GART (Graphics Address Relocation Table) + hardware included on Tegra SoCs. + endif # IOMMU_SUPPORT diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 0e36b49..3238a31 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_IRQ_REMAP) += intr_remapping.o obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o obj-$(CONFIG_OMAP_IOVMM) += omap-iovmm.o obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o +obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c new file mode 100644 index 0000000..f6be902 --- /dev/null +++ b/drivers/iommu/tegra-gart.c @@ -0,0 +1,451 @@ +/* + * IOMMU API for GART in Tegra20 + * + * Copyright (c) 2010-2012, NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#define pr_fmt(fmt) "%s(): " fmt, __func__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* bitmap of the page sizes currently supported */ +#define GART_IOMMU_PGSIZES (SZ_4K) + +#define GART_CONFIG 0x24 +#define GART_ENTRY_ADDR 0x28 +#define GART_ENTRY_DATA 0x2c +#define GART_ENTRY_PHYS_ADDR_VALID (1 << 31) + +#define GART_PAGE_SHIFT 12 +#define GART_PAGE_SIZE (1 << GART_PAGE_SHIFT) +#define GART_PAGE_MASK \ + (~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID) + +struct gart_client { + struct device *dev; + struct list_head list; +}; + +struct gart_device { + void __iomem *regs; + u32 *savedata; + u32 page_count; /* total remappable size */ + dma_addr_t iovmm_base; /* offset to vmm_area */ + spinlock_t pte_lock; /* for pagetable */ + struct list_head client; + spinlock_t client_lock; /* for client list */ + struct device *dev; +}; + +static struct gart_device *gart_handle; /* unique for a system */ + +#define GART_PTE(_pfn) \ + (GART_ENTRY_PHYS_ADDR_VALID | ((_pfn) << PAGE_SHIFT)) + +/* + * Any interaction between any block on PPSB and a block on APB or AHB + * must have these read-back to ensure the APB/AHB bus transaction is + * complete before initiating activity on the PPSB block. + */ +#define FLUSH_GART_REGS(gart) ((void)readl((gart)->regs + GART_CONFIG)) + +#define for_each_gart_pte(gart, iova) \ + for (iova = gart->iovmm_base; \ + iova < gart->iovmm_base + GART_PAGE_SIZE * gart->page_count; \ + iova += GART_PAGE_SIZE) + +static inline void gart_set_pte(struct gart_device *gart, + unsigned long offs, u32 pte) +{ + writel(offs, gart->regs + GART_ENTRY_ADDR); + writel(pte, gart->regs + GART_ENTRY_DATA); + + dev_dbg(gart->dev, "%s %08lx:%08x\n", + pte ? "map" : "unmap", offs, pte & GART_PAGE_MASK); +} + +static inline unsigned long gart_read_pte(struct gart_device *gart, + unsigned long offs) +{ + unsigned long pte; + + writel(offs, gart->regs + GART_ENTRY_ADDR); + pte = readl(gart->regs + GART_ENTRY_DATA); + + return pte; +} + +static void do_gart_setup(struct gart_device *gart, const u32 *data) +{ + unsigned long iova; + + for_each_gart_pte(gart, iova) + gart_set_pte(gart, iova, data ? *(data++) : 0); + + writel(1, gart->regs + GART_CONFIG); + FLUSH_GART_REGS(gart); +} + +#ifdef DEBUG +static void gart_dump_table(struct gart_device *gart) +{ + unsigned long iova; + unsigned long flags; + + spin_lock_irqsave(&gart->pte_lock, flags); + for_each_gart_pte(gart, iova) { + unsigned long pte; + + pte = gart_read_pte(gart, iova); + + dev_dbg(gart->dev, "%s %08lx:%08lx\n", + (GART_ENTRY_PHYS_ADDR_VALID & pte) ? "v" : " ", + iova, pte & GART_PAGE_MASK); + } + spin_unlock_irqrestore(&gart->pte_lock, flags); +} +#else +static inline void gart_dump_table(struct gart_device *gart) +{ +} +#endif + +static inline bool gart_iova_range_valid(struct gart_device *gart, + unsigned long iova, size_t bytes) +{ + unsigned long iova_start, iova_end, gart_start, gart_end; + + iova_start = iova; + iova_end = iova_start + bytes - 1; + gart_start = gart->iovmm_base; + gart_end = gart_start + gart->page_count * GART_PAGE_SIZE - 1; + + if (iova_start < gart_start) + return false; + if (iova_end > gart_end) + return false; + return true; +} + +static int gart_iommu_attach_dev(struct iommu_domain *domain, + struct device *dev) +{ + struct gart_device *gart; + struct gart_client *client, *c; + int err = 0; + + gart = dev_get_drvdata(dev->parent); + if (!gart) + return -EINVAL; + domain->priv = gart; + + client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL); + if (!client) + return -ENOMEM; + client->dev = dev; + + spin_lock(&gart->client_lock); + list_for_each_entry(c, &gart->client, list) { + if (c->dev == dev) { + dev_err(gart->dev, + "%s is already attached\n", dev_name(dev)); + err = -EINVAL; + goto fail; + } + } + list_add(&client->list, &gart->client); + spin_unlock(&gart->client_lock); + dev_dbg(gart->dev, "Attached %s\n", dev_name(dev)); + return 0; + +fail: + devm_kfree(gart->dev, client); + spin_unlock(&gart->client_lock); + return err; +} + +static void gart_iommu_detach_dev(struct iommu_domain *domain, + struct device *dev) +{ + struct gart_device *gart = domain->priv; + struct gart_client *c; + + spin_lock(&gart->client_lock); + + list_for_each_entry(c, &gart->client, list) { + if (c->dev == dev) { + list_del(&c->list); + devm_kfree(gart->dev, c); + dev_dbg(gart->dev, "Detached %s\n", dev_name(dev)); + goto out; + } + } + dev_err(gart->dev, "Couldn't find\n"); +out: + spin_unlock(&gart->client_lock); +} + +static int gart_iommu_domain_init(struct iommu_domain *domain) +{ + return 0; +} + +static void gart_iommu_domain_destroy(struct iommu_domain *domain) +{ + struct gart_device *gart = domain->priv; + + if (!gart) + return; + + spin_lock(&gart->client_lock); + if (!list_empty(&gart->client)) { + struct gart_client *c; + + list_for_each_entry(c, &gart->client, list) + gart_iommu_detach_dev(domain, c->dev); + } + spin_unlock(&gart->client_lock); + domain->priv = NULL; +} + +static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t pa, size_t bytes, int prot) +{ + struct gart_device *gart = domain->priv; + unsigned long flags; + unsigned long pfn; + + if (!gart_iova_range_valid(gart, iova, bytes)) + return -EINVAL; + + spin_lock_irqsave(&gart->pte_lock, flags); + pfn = __phys_to_pfn(pa); + if (!pfn_valid(pfn)) { + dev_err(gart->dev, "Invalid page: %08x\n", pa); + spin_unlock(&gart->pte_lock); + return -EINVAL; + } + gart_set_pte(gart, iova, GART_PTE(pfn)); + FLUSH_GART_REGS(gart); + spin_unlock_irqrestore(&gart->pte_lock, flags); + return 0; +} + +static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova, + size_t bytes) +{ + struct gart_device *gart = domain->priv; + unsigned long flags; + + if (!gart_iova_range_valid(gart, iova, bytes)) + return -EINVAL; + + spin_lock_irqsave(&gart->pte_lock, flags); + gart_set_pte(gart, iova, 0); + FLUSH_GART_REGS(gart); + spin_unlock_irqrestore(&gart->pte_lock, flags); + return 0; +} + +static phys_addr_t gart_iommu_iova_to_phys(struct iommu_domain *domain, + unsigned long iova) +{ + struct gart_device *gart = domain->priv; + unsigned long pte; + phys_addr_t pa; + unsigned long flags; + + if (!gart_iova_range_valid(gart, iova, 0)) + return -EINVAL; + + spin_lock_irqsave(&gart->pte_lock, flags); + pte = gart_read_pte(gart, iova); + spin_unlock_irqrestore(&gart->pte_lock, flags); + + pa = (pte & GART_PAGE_MASK); + if (!pfn_valid(__phys_to_pfn(pa))) { + dev_err(gart->dev, "No entry for %08lx:%08x\n", iova, pa); + gart_dump_table(gart); + return -EINVAL; + } + return pa; +} + +static int gart_iommu_domain_has_cap(struct iommu_domain *domain, + unsigned long cap) +{ + return 0; +} + +static struct iommu_ops gart_iommu_ops = { + .domain_init = gart_iommu_domain_init, + .domain_destroy = gart_iommu_domain_destroy, + .attach_dev = gart_iommu_attach_dev, + .detach_dev = gart_iommu_detach_dev, + .map = gart_iommu_map, + .unmap = gart_iommu_unmap, + .iova_to_phys = gart_iommu_iova_to_phys, + .domain_has_cap = gart_iommu_domain_has_cap, + .pgsize_bitmap = GART_IOMMU_PGSIZES, +}; + +static int tegra_gart_suspend(struct device *dev) +{ + struct gart_device *gart = dev_get_drvdata(dev); + unsigned long iova; + u32 *data = gart->savedata; + unsigned long flags; + + spin_lock_irqsave(&gart->pte_lock, flags); + for_each_gart_pte(gart, iova) + *(data++) = gart_read_pte(gart, iova); + spin_unlock_irqrestore(&gart->pte_lock, flags); + return 0; +} + +static int tegra_gart_resume(struct device *dev) +{ + struct gart_device *gart = dev_get_drvdata(dev); + unsigned long flags; + + spin_lock_irqsave(&gart->pte_lock, flags); + do_gart_setup(gart, gart->savedata); + spin_unlock_irqrestore(&gart->pte_lock, flags); + return 0; +} + +static int tegra_gart_probe(struct platform_device *pdev) +{ + struct gart_device *gart; + struct resource *res, *res_remap; + void __iomem *gart_regs; + int err; + struct device *dev = &pdev->dev; + + if (gart_handle) + return -EIO; + + BUILD_BUG_ON(PAGE_SHIFT != GART_PAGE_SHIFT); + + /* the GART memory aperture is required */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + res_remap = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!res || !res_remap) { + dev_err(dev, "GART memory aperture expected\n"); + return -ENXIO; + } + + gart = devm_kzalloc(dev, sizeof(*gart), GFP_KERNEL); + if (!gart) { + dev_err(dev, "failed to allocate gart_device\n"); + return -ENOMEM; + } + + gart_regs = devm_ioremap(dev, res->start, resource_size(res)); + if (!gart_regs) { + dev_err(dev, "failed to remap GART registers\n"); + err = -ENXIO; + goto fail; + } + + gart->dev = &pdev->dev; + spin_lock_init(&gart->pte_lock); + spin_lock_init(&gart->client_lock); + INIT_LIST_HEAD(&gart->client); + gart->regs = gart_regs; + gart->iovmm_base = (dma_addr_t)res_remap->start; + gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT); + + gart->savedata = vmalloc(sizeof(u32) * gart->page_count); + if (!gart->savedata) { + dev_err(dev, "failed to allocate context save area\n"); + err = -ENOMEM; + goto fail; + } + + platform_set_drvdata(pdev, gart); + do_gart_setup(gart, NULL); + + gart_handle = gart; + return 0; + +fail: + if (gart_regs) + devm_iounmap(dev, gart_regs); + if (gart && gart->savedata) + vfree(gart->savedata); + devm_kfree(dev, gart); + return err; +} + +static int tegra_gart_remove(struct platform_device *pdev) +{ + struct gart_device *gart = platform_get_drvdata(pdev); + struct device *dev = gart->dev; + + writel(0, gart->regs + GART_CONFIG); + if (gart->savedata) + vfree(gart->savedata); + if (gart->regs) + devm_iounmap(dev, gart->regs); + devm_kfree(dev, gart); + gart_handle = NULL; + return 0; +} + +const struct dev_pm_ops tegra_gart_pm_ops = { + .suspend = tegra_gart_suspend, + .resume = tegra_gart_resume, +}; + +static struct platform_driver tegra_gart_driver = { + .probe = tegra_gart_probe, + .remove = tegra_gart_remove, + .driver = { + .owner = THIS_MODULE, + .name = "tegra-gart", + .pm = &tegra_gart_pm_ops, + }, +}; + +static int __devinit tegra_gart_init(void) +{ + bus_set_iommu(&platform_bus_type, &gart_iommu_ops); + return platform_driver_register(&tegra_gart_driver); +} + +static void __exit tegra_gart_exit(void) +{ + platform_driver_unregister(&tegra_gart_driver); +} + +subsys_initcall(tegra_gart_init); +module_exit(tegra_gart_exit); + +MODULE_DESCRIPTION("IOMMU API for GART in Tegra20"); +MODULE_AUTHOR("Hiroshi DOYU "); +MODULE_LICENSE("GPL v2"); -- 1.7.5.4